FYI, most restaurants have vegetarian options, with the exception of:
Steak, Seafood, Cuban, Brazillian, and Filipino restaurants. Not that I'm recommending chain restaurants, but the only chain restaurant that I have had trouble finding something that does not fit in these categories, is Applebees, and their food is terrible anyways. I'm just mentioning chain restaurants because their menus are typically the same throughout the country.
It is usually pretty easy to find vegetarian food in:
Mediterranean, Mexican, Greek, Italian, Chinese, Thai, Ethiopian, Indian, etc.
American: Red Robin, any burger can use a boca or garden burger patty substitute.
Anyways, it is a personal decision and people need to decide what is right for them.
Vegetarian Restaurant Directory: http://www.happycow.net/